Space News & Blog Articles

Webb is fully operational again, Rolls-Royce is building a nuclear reactor for the Moon, and the space debris worst-case scenario almost happened.

James Webb is Back

Last week was tough for James Webb Space Telescope news when we learned that NASA had taken the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument offline on January 15th. The instrument was experiencing communications errors and software delays, so NASA put the instrument into safe mode. After some analysis, they discovered that the device was hit by a galactic cosmic ray that messed up its memory. They turned it off and back on again, and it was good as new, ready for more science.

More about JWST’s problems.

Rolls-Royce Nuclear Reactor

Rolls-Royce revealed new details about their micro-nuclear reactor that could provide both rocket propulsion in space and power generation at remote locations like the Moon and Mars. The reactor is being developed through a partnership with the UK Space Agency and could provide power in various scales, from “watts to megawatts.” They claim to keep the uranium fuel safe by encapsulating each particle in multiple protective layers that act as an a. containment system.

More about RR space reactor.

Over over 50% of high mass stars reside in multiple star systems. But due to their complex orbital interactions, physicists have a difficult time understanding just how stable and long-lived these systems are. Recently a team of astronomers applied machine learning techniques to simulations of multiple star systems and found a new way that stars in such systems can arrange themselves.

Classical mechanics has a notorious problem known as the three-body problem. While Newton’s laws of gravity can easily handle calculations of the forces between two objects and their subsequent evolution, there is no known analytic solution when you include a third massive object. In response to that problem, physicists over the centuries have developed various approximation schemes to study these kinds of systems, concluding that the vast majority of possible three-object arrangements are unstable.

But it turns out that there are a lot of multiple-star systems out there in the galaxy. Indeed, over half of all massive stars belong to at least a binary pair, and many of them belong to triple or quadruple star systems. Obviously the systems last a long time, otherwise they would have flung themselves apart a long time ago before we had a chance to observe them. But because of the limitations of our tools we have difficulty assessing how these systems organize themselves and what the stable orbit options exist.

Recently a team of astronomers conducted tens of thousands of simulations of quadruple star systems, varying the mass and orbital distances of all the objects. They then ran the simulation outputs through a machine learning classifier to pull out general trends and categories for the structures of the stable orbits.

They found one such structure of orbits that was already familiar to old analytic techniques. This is the so-called nested triple system. You start with two stars close together orbiting around a common center of mass. Then you add a third star in a large enough orbit around those other two so that from that distance the other two might as well be a single star. Then to add a fourth star you put it at an even greater distance so it orbits around the other three.

A team of astronomers have used a model of earthquakes to understand glitches in the timing of pulsars. Their results suggest that pulsars may have interiors that are far stranger than can be imagined.

Pulsars are perhaps the most accurate timekeepers in the entire universe. The pulsars themselves are really rapidly spinning neutron stars. Neutron stars are ultra-dense balls of atomic matter, usually no bigger than a few miles across with a mass a few times that of the Sun. 

When these neutron stars spin they blast out beams of radiation that draw circles around the sky. If the Earth happens to lie on one of those circles then we see a periodic flashing from those beams of radiation, creating a pulsar.

Pulsars will keep accurate rhythm for incredibly long periods of time. But occasionally they are known to glitch, when they suddenly shift from one rotation rate to another.

Astronomers do not fully understand what causes the glitches, but recently a team of researchers put together a model of how glitches operate. The model is based on earthquakes. Earthquakes have many causes, but one of them is when too much tension and pressure builds up between tectonic plates and the crust of the Earth buckles under the pressure. That results in an earthquake and a resettling of the material in the Earth.